Add keyword to filter list (blocks URLs containing the keyword)
AI agents use add_keyword_filter to create or update resources in ASUS Merlin Router MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your ASUS Merlin Router MCP Server environment.
This tool creates or modifies configuration data (a keyword filter rule) reversibly without deleting data or executing arbitrary commands. While it affects network traffic by blocking content, the action itself is a write operation that can be undone by removing the keyword filter.
From the tool's definition Tool explicitly performs an 'add' operation that 'blocks URLs containing the keyword' by adding to a filter list, creating a new filtering rule reversibly.
Documented attack patterns abuse exactly the kind of access add_keyword_filter gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and ASUS Merlin Router MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for add_keyword_filter:
{
"version": "1",
"default": "deny",
"tools": {
"add_keyword_filter": {
"limits": [
{
"counter": "add_keyword_filter_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}add_keyword_filter stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Add keyword to filter list (blocks URLs containing the keyword). It is categorised as a Write tool in the ASUS Merlin Router MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the ASUS Merlin Router MCP Server MCP server in PolicyLayer and add a rule for add_keyword_filter: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches ASUS Merlin Router MCP Server. Nothing to install.
add_keyword_filter is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the add_keyword_filter rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for add_keyword_filter. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
add_keyword_filter is provided by the ASUS Merlin Router MCP Server MCP server (kcsoukup/asus-merlin-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from ASUS Merlin Router MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
47 ASUS Merlin Router MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.